Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Ambugaton on June 10, 2016, 01:51:18 pm
-
I'm still a complete novice on amp designs/circuits but pretty keen on knowing what sound I like and don't like. I just think this combination will result in the perfect bass response and punchiness that I desire. I am probably going to start this build in a couple weeks still but figured there's plenty to learn before I take the plunge. This will be my 3rd amp with very minimal electronics experience so bear with me...
1) Would there need to be any changes to the Deluxe Lite schematic for the KT66s? I know that KT66s can swap with 6L6s but not sure about the 6V6. Maybe the OT hookups would need to be altered? More or less - bias voltage?
2) Without the reverb and vibrato what size chassis could I reasonably expect to fit this in? Does Doug offer a chassis and/or turret board that will work for this project? (I am more so asking this to keep it in mind and know that I can do my own research on this)
3) What current production KT66s are favored? I have tried the JJs but have read many articles saying they are not "true" KT66s.
Thanks
-
My schematic and layout would work fine. Probably need a bit more bias voltage (easy to do) and I would change the 10K B+ dropping resistors to 1K and 4.7K like most of the 6L6 AB763s use. I could build this in a 12 x 6.5 x 2.5 blank chassis. Doug offers the chassis and can even make any turret board from your drawing. He already offers a single channel AB763 with reverb and tremolo. That could be a basis for modification to remove reverb and trem if you wanted to go that way.
p2pAmps just did a KT66 DR. I'm sure he can answer any of your questions about this, especially KT66 specific questions. Take a look...
http://el34world.com/Forum/index.php?topic=20136.0 (http://el34world.com/Forum/index.php?topic=20136.0)
-
p2pAmps just did a KT66 DR. I'm sure he can answer any of your questions about this, especially KT66 specific questions. Take a look...
http://el34world.com/Forum/index.php?topic=20136.0 (http://el34world.com/Forum/index.php?topic=20136.0)
And it sounds superb. Way nice.
-
Yeah I saw his thread and it's the reason I know this is what I need to build!
I think I am going to go SS rectifier. I am unfamiliar with how to place that into the circuit but I know I have seen a couple posts about it. I believe it is just a couple of the 1N4007 diodes placed in the bias circuit?
I am still unsure which chassis to use? The DR chassis is overkill for the lite version. The stout chassis would seems like it meets my needs just not sure if the DR PT will fit.
Last thing is that I would like to use the JJ cap can to save room but I am unsure how the 10K resistors will be installed. I assume the A, B, C, D translate to Y, X, U, O respectively?
Like I said, I appreciate anyone that gives me their time for these basic questions.
-
I am still unsure which chassis to use? The DR chassis is overkill for the lite version. The stout chassis would seems like it meets my needs just not sure if the DR PT will fit.
I'm pretty sure the DR PT is insufficient for a KT66 build. PtPamps used a Tweed Bassman PT from Classic Tone http://www.classictone.net/40-18073.html (http://www.classictone.net/40-18073.html)
here's the chassis cutout dims of that PT http://www.classictone.net/OOA-85285_Chassis_Cutout_C-400.pdf (http://www.classictone.net/OOA-85285_Chassis_Cutout_C-400.pdf)
or you could use a Super Reverb PT or equivalent 50W pt with enough current to power the power tubes and the filaments. That tweed Bassman PT is 200 ma rated. DR only 100 ma.
I'm sure you'd have to modify the Stout chassis PT opening for bigger iron, which is doable. The PT width is cool but the Bassman PT requires a .38" longer opening. Still doable with a little work and a dremel.
-
Last thing is that I would like to use the JJ cap can to save room but I am unsure how the 10K resistors will be installed. I assume the A, B, C, D translate to Y, X, U, O respectively?
Yes sir, that is correct correlation of the cap can to the PS nodes on the schematic. I assume you are using a JJ 40/20/20/20 cap can.Where are you mounting it? If you plan on mounting it in the hole for the rectifier, that hole may need to enlarged to accommodate the cap can.
-
I've come to terms with the fact that I am not at the point in my amp building and knowledge to begin designing and modifying an amp before it is together and working.
I think I am leaning towards a portable/flexible Princeton Reverb. Does anyone have any first hand with the Princeton and the Deluxe side by side? 15W/22W is not that much of a difference. Do they sound similar? I listen to someone like Jim Campilongo with a tele/PR and I don't know if it gets any better.
To satisfy my constant need to have the option to tweak and adjust maybe I will add something like a NFB pot... or some other common and "easy" mods...
-
Sounds like you need one of each. And a Tele. :icon_biggrin:
-
Ambugaton when I first started building I would add NFB pots to all my builds. Because there is a sweet spot that to my ears sounds the best. the problem was once you find it you don't change it. So I just have one in my tools box pull it out find the sweet spot and put in the proper resisters to get there.
Bill
-
That might be something I try down the road. I do know that today's sweet spot doesn't sound as good tomorrow. To me at least... anyone else have that problem?